IL94373A - Process for the preparation of 3,5,6-trichloropyridin-2-ol - Google Patents
Process for the preparation of 3,5,6-trichloropyridin-2-olInfo
- Publication number
- IL94373A IL94373A IL9437390A IL9437390A IL94373A IL 94373 A IL94373 A IL 94373A IL 9437390 A IL9437390 A IL 9437390A IL 9437390 A IL9437390 A IL 9437390A IL 94373 A IL94373 A IL 94373A
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- chloride
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- tetrachloro
- organic solvent
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D213/00—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members
- C07D213/02—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D213/00—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members
- C07D213/02—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members
- C07D213/04—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom
- C07D213/60—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
- C07D213/62—Oxygen or sulfur atoms
- C07D213/63—One oxygen atom
- C07D213/64—One oxygen atom attached in position 2 or 6
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C255/00—Carboxylic acid nitriles
- C07C255/01—Carboxylic acid nitriles having cyano groups bound to acyclic carbon atoms
- C07C255/19—Carboxylic acid nitriles having cyano groups bound to acyclic carbon atoms containing cyano groups and carboxyl groups, other than cyano groups, bound to the same saturated acyclic carbon skeleton
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Pyridine Compounds (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
- Catalysts (AREA)
- Nitrogen Condensed Heterocyclic Rings (AREA)
- Manufacture Of Tobacco Products (AREA)
- Hydrogenated Pyridines (AREA)
Abstract
A process for the preparation of 3,5,6-trichloropyridin-2-ol from trichloroacetyl chloride and acrylonitrile is improved by separately conducting the individual addition, cyclization and aromatization steps. By separating these steps, water and HCl, which are by-products of the latter steps, can be precluded from interfering with the earlier steps. The individual process steps have also been improved.
Description
36,327-F AN IMPBOVED PROCESS FOB THE PBEPA RATION OF 3.5,6- TBICHLOROPYR ID IN-2-0L ¾ΐΝ-2-ντ*"ΐ>- ι½3>Ίϋ-6,5,3 i n -]-> nn ABSTRACT A process for the preparation of 3 » , 6 --trichloropyridin-2-ol from trichloroacetyl chloride and acrylonitrile is improved by separately conducting the individual addition, cyclization and aromatiza-tion steps. By separating these steps, water and HC1, which are by-products of the latter steps, can be precluded from interfering with the earlier steps. The individual process steps have also been improved. 6,327-F -1- AN IMPROVED PROCESS FOR THE PREPARATION OF 3,5,6-TRICHLOROPYRIDIN-2-OL The present invention concerns an improved process for preparing 3 » 5 , 6-trichloropyridin-2-ol from trichloroacetyl chloride and acryloni tri le . 3 , , 6-Trichloropy idin-2-ol is an intermediate in the manufacture of several agricultural pesticides, e.g., chlorpyri os , chlorpyrifos-methyl and triclopyr. U.S. Patent 4,327,216 describes a process for preparing a mixture of 2 , 3 > 5 , 6-tetrachloropyridine and 3*5,6--trichloropyridin-2-ol by reacting trichloroacetyl chloride with acrylonitrile in the presence of a catalyst .
The following series, of reactions is responsible for the products obtained in said patent ( Scheme I ) . 6,327-F Scheme I Although the series of reactions is advantageously carried out in a single operation and in a closed system under pressure, the combined yield of 2 , 3 » 5 , 6-tetra- chloropyr idine and 3 » 5 , 6-trichloropyr idin-2-ol is not very high. Furthermore, the reaction typically produces a mixture of the two products which must be separated or treated in subsequent operations to convert one product into the other. It is desirable to have a process to 6,327-F -2- prepare 3 » 5 , 6-tr ichloropyr idin-2-ol in higher yields and without any tetrachloropyr idine by-product.
It is further disclosed in Chemical Abstracts , 111/ 730 (1989), abstract number 97100d that 3 , 5 , 6-trichloro 2-pyridinol can be preapred by heating a solution of trichloroacetylchloride and acrylonitrile in nitrobenzene containing cuprous chloride catalyst for a period, subsequently adding a base, and finally acidifying with an acid.
The present invention is directed to an improved process for preparing 3 > 5 , 6-trichloropyr idin-2--ol which comprises the following steps: (a) reacting tr ichloroacetyl chloride with acrylonit ile at a temperature from 50 to 140°C in the presence of a catalytic amount of copper or a cuprous salt to produce 2,2, 4-tr ichloro-4-cyanobutanoyl chloride while removing any HC1 formed by operating under reflux conditions; (b) reacting the 2 , 2 , 4-trichloro-4-cyano- butanoyl chloride in an inert organic solvent with anhydrous HC1 at a pressure from 136 to 1,480 kPa and at a temperature from ambient to 100°C to cyclize the butanoyl chloride to 3 » 3 > 5 , 6-tetrachloro- -3 j 4-dihydropyridin-2-one ; and (c) reacting the 3 , 3 , 5 , 6-tetrachloro-3 , 4- diliydropyridiii-2-one with chloride°and a phase transfer catalyst in an inert organic solvent to produce the 3,5,G-Lrichloro-2-pyridinol .
The present invention is further directed to the various process improvements as they relate to the individual steps .
It has been found that 3 , 5 , 6-trichloropyri- din-2-ol can be prepared in high yield and without tetrachloropyr idine as a by-product by conducting the -U- addition, cyclization and aromatization reactions separately .
Addition: Aromatization: The first reaction, the addition reaction of trichloroacetyl chloride to acryloni tri le produces 2,2,4-trichloro-4-cyanobutanoyl chloride, which cyclizes in the presence of HC1. The cyclization intermediate, depending on whether HC1 or is eliminated, can yield one of three products: 3 , 3 > 5 , 6-tetrachloro-3 , -dihydro-pyridin-2-one ; 3 » , 6-tr ichloropyridin-2-οϊ ; or 2.3 » 5 , 6--tetrachloropyridine .
It has now been found that the water produced during the formation of the tetrachloropyridine is a 6,327-F -4- -o- major contributor to yield loss via numerous side reactions. Water can be formed during the cyclization process which itself is acid catalyzed. The present invention provides a process for achieving better yields by removing any HC1 formed by decomposition of the reactants during the addition step. For convenience, HC1 is removed and hence water formation is precluded by preferentially conducting the addition reaction under reflux.
Trichloroacetyl chloride (TCAC) and acrylonitrile (VCN) are items of commerce and are routinely distilled prior to use. The trichloroacetyl chloride and acrylonitrile can be reacted in molar ratios ranging from stoichiometric, i.e., 1:1, to a 2 to 3 fold excess of either reagent, i.e., 1:3 to 3:1 VCN/TCAC. Ratios of VCN/TCAC of 1.1 to 1.3 are generally preferred.
The addition reaction is carried out in the presence of a catalytic amount of a cuprous salt under an inert atmosphere, such as, for example, nitrogen or argon. Cuprous salts that can be employed include, for example, the chloride, bromide, iodide, oxide or acetate, preferably the halides. Catalysts that are partially oxidized to the cupric oxidation state or are hydrated are less effective than the pure materials. The addition of copper metal, which itself can be oxidized to the cuprous oxidation state while simultaneously preventing further oxidation to the cupric oxidation state, can advantageously be employed. The cuprous catalyst is usually employed in an amount corresponding to from 0.005 to 0.05 moles of catalyst 6,327-F -5- -o- per mole of trichloroacetyl chloride, although larger proportions can be used.
The addition reaction may be carried out neat or in the presence of an inert solvent. Alkylnitriles , such as acetoni trile , are commonly used for the cuprous catalyzed addition of polyhalogen compounds to olefins. However, the addition of acetonitrile to the reaction mixture does not provide any beneficial effects.
Therefore, the reaction is preferably conducted neat or ^ with excess TCAC or VCN effectively serving as the solvent. Trichloroacetyl chloride can be commercially prepared by the photochemical oxidation of perchloro- ethylene; see, for example, U.S. Patent 2,M27,621J.
^ Prepared by this procedure, TCAC typically contains about 15 percent residual perchloroethylene . Perchloro- ethylene has no negative effect on the addition chemistry. 2Q To prevent the production of HC1 by the premature cyclization of 2 , 2 , 4-trichloro-4-cyano- butanoyl chloride, reaction temperatures should be maintained from 50 to 140°C. To remove any HC1 produced by the decomposition of TCAC, the reaction is run at 25 reflux. The reflux temperature is determined by the composition of the mixture. Ideally, the temperature should be maintained between 70-120°C, preferably between 80-105°C. The preferred temperatures are conveniently between the boiling points of VCN and TCAC ^ at atmospheric pressure. When the reaction is conducted neat or with VCN or TCAC in excess as an effective solvent, the reflux temperature gradually increases as 36,327-F -6- -7- the lower boiling reactants are converted to higher boiling product.
The addition reaction is preferably conducted under an inert atmosphere, such as, for example, under a nitrogen or argon blanket. Although conveniently conducted at atmospheric pressure, the reaction is preferably run under a slight positive pressure of up to 136 kPa (5 psig) of the blanketing inert gas which helps in keeping the reaction mixture dry.
In a typical reaction, freshly distilled TCAC, VCN and anhydrous CuCl are heated under reflux in a nitrogen atmosphere. After the addition reaction is complete, generally in from 8 to 48 hours (hrs), the product 2, 2 , 4-tr ichloro-4-cyanobutanoyl chloride can be recovered by conventional techniques. The product can be conveniently isolated, for example, by evaporating any volatile TCAC or VCN, adding a suitable solvent in which the spent copper catalyst is not soluble and in which the subsequent cyclization reaction can be advantageously conducted, and removing the catalyst by filtration. Suitable solvents include aromatic hydrocarbons, halogenated hydrocarbons and carboxylic acid esters. Product of greater than 90 percent purity can be obtained by evaporation of the solvent.
Alternatively, the filtrate so obtained can be used directly in the subsequent cyclization reaction.
The cyclization of 2 , 2 , 4-tr ichloro-4-cyano-butanoyl chloride to 3 , 3 , 5 , 6-tetrachloro-3 , 4-dihydro-pyr idin-2-one is catalyzed by acidic reagents, preferably in an anhydrous state. The cyclization is conveniently carried out, for example, by reacting the 2 , 2 , 4-trichloro-4-cyanobutanoyl chloride with anhydrous 6,327-F -7- -3- HC1. Simply sparging anhydrous HC1 into the 2,2,4--trichloro-4-cyanobutanoyl chloride at atmospheric pressure in the absence of a solvent does not accomplish cyclization. Since higher temperatures lead to greater amounts of dehydration and tetrachloropyr idine formation, it is beneficial to keep the temperature below 100°C. The cyclization reaction is effectively run from ambient temperature to 100°C, preferably from 40° to 60°C. In order to keep the reaction mixture mobile at temperatures below the melting point of the product and in order to keep the anhydrous HC1 in effective contact with the reaction mixture, it is preferable to conduct the cyclization under pressure in the presence of a solvent. Pressures from 136 to 1,480 kPa (5 to 200 psig) are routinely employed; those from 273 to 1,135 kPa (25 to 150 psig) are preferred.
Suitable solvents for the cyclization reaction include aromatic hydrocarbons, halogenated hydrocarbons and carboxylic acid esters. Examples of suitable solvents of each class include but are not limited to the following: toluene and xylenes; methylene chloride, ethylene dichloride (EDC) and perchloroethylene (PERC); and ethyl acetate.
The cyclization reaction may be conveniently conducted in a batch reaction or in a continuous fashion in a coil reactor. In a typical reaction, 2,2,4-tri-chloro-4-cyanobutanoyl chloride is diluted with the desired solvent in a closed pressure vessel, and the vessel is pressurized with anhydrous HC1 to the desired pressure. The reaction mixture is stirred at the appropriate temperature until the reaction is completed, usually from one to three hours. The reaction vessel is vented and the product, 3 » 3 , , 6-tetrachloro-3 » 4- 6,327-F -3- -9- -dihydropyr idin-2-one , can be isolated by conventional procedures. For example, evaporation of the solvent provides a crude solid product which can be slurried with an aliphatic hydrocarbon, such as hexane, and which can then be isolated by filtration. Product so obtained is sufficiently pure after drying to be used in the subsequent aromatization. Alternatively, the crude reaction mixture can be used directly, immediately after venting and removal of the HC1.
The aromatization of 3 » 3 , 5 , 6-tetrachloro-3 , 4--dihydropyridin-2-one to 3 , 5 , 6-tr ichloropyr idin-2-ol can be accomplished in a variety of ways. Among the most effective procedures are treatment in a two-phase system with an aqueous base or treatment with chloride ion in an organic solvent.
Since the desired product, 3 > 5 , 6-tr ichloro-pyridin-2-ol , is often used as the sodium salt, it is often convenient to conduct the aromatization with aqueous alkaline solutions. The reaction is preferably run in a two-phase system using a water immiscible organic solvent. Suitable solvents for the aromatization reaction include aromatic hydrocarbons, halogenated hydrocarbons and carboxylic acid esters. Examples of suitable solvents of each class include but are not limited to the following: toluene and xylenes; methylene chloride, ethylene dichloride and perchloro-ethylene; and ethyl acetate. Naturally, it is preferable- to emp.loy the same solvent that has previously been used in the cyclization reaction.
The aromatization reaction requires the use of at least two equivalents of base per equivalent of 3 > 3 » 5 , 6-tetrachloro-3 , 4-dihydropyr idin-2-one . One 6,327-F -9- -10- equivalent is required for the elimination of one mole of HCl, while the second equivalent is consumed in converting the pyridinol to the pyridinate. If desired, larger proportions of base may be employed. Suitable bases include but are not limited to the alkali metal hydroxides and carbonates. Sodium or potassium carbonate are generally preferred, particularly for the carboxylic acid ester solvents which are susceptible to reaction with dilute caustic at room temperature.
^ In a typical reaction, the base, dihydro- pyridone, solvent and water are contacted with stirring at a temperature of from ambient to 100°C or the reflux temperature of the mixture. After the reaction is ^ complete, generally in from 2 to 24 hrs, the 3,5,6- -trichloropy idin-2-ol is isolated by conventional procedures. For example, tr ichloropyridinol may simply be isolated by acidifying the reaction mixture and separating the organic phase. After drying the organic 0 solution, evaporation of the solvent provides the desired pyridinol. Alternatively, if the alkali metal salt of the trichloropyr idinol is desired, an aqueous solution of the pyridinate may be obtained by simply separating the aqueous reaction phase. 5 Alternatively, the aromatization reaction can be accomplished by treating the 3 , 3 > 5 , 6-tetrachloro-3 > 4- -dihydropyridin-2-one with chloride ion in an inert organic solvent. The chloride ion may be added directly or may be generated insitu by initiating the elimination of HCl from the pyridone. Since chloride ion is generated by the elimination of HCl from the substrate, only catalytic quantities of chloride ion or of a material capable of initiating the elimination of HCl are needed. Suitable catalysts contemplated by the 36,327-F -10- -11- above definition include but are not limited to the following types of materials: tertiary or aromatic amine bases, such as, for example, trialkyl amines, pyridine, picolines or lutidines; quaternary ammonium or phosphonium salts, such as, for example, tetraalkyl or aryl ammonium or phosphonium halides; crown ether complexes, such as, for example, l8-Crown-6/KCl ; and ion exchange resins, particularly amine resins such as, for example, MSA-1 Dow Ion Exchange Resin. Specific examples of suitable materials include the following: tetrabutylammonium halides, tetraphenylphosphonium halides, nonyltriphenylphosphonium halides, benzyl-triethylammonium halides, pyridinium halides and poly ( 4-vinylpyridine ) . MSA-1 Dow Ion Exchange Resin and tetrabutylammonium chloride are among the preferred catalysts. These catalysts are usually employed in an amount corresponding to from 0.002 to 0.2 moles of catalyst per mole of 3 » 3 i , 6-tetrachloro-3 , 4--dihydropyridin-2-one , preferably from 0.005 to 0.05 moles of catalyst per mole of dihydropyridone .
Suitable solvents for the aromatization reaction include the same aromatic hydrocarbons, halogenated hydrocarbons and carboxylic acid esters employed in the previous steps. Perchloroethylene is a particularly preferred solvent for this reaction.
The reaction is conducted at a temperature from between 40° to 120°C, preferably at the reflux temperature of the mixture.
In a typical reaction, the 3 > 3 > 5 , 6-tetrachloro--3 > -dihydropyridin-2-one is contacted with the catalyst and solvent, and the reaction mixture is heated to reflux. After the reaction is complete, generally in 6,327-F -11- -12- from 1 to 3 hrs , the desired 3 > 5 , 6-tr ichloropyr idin-2--ol can be isolated by conventional techniques. For example, if an insoluble catalyst such as MSA-1 Dow Ion Exchange Resin is employed, the catalyst can be removed by filtration while hot and can be recovered and recycled in subsequent reactions. After the removal of the catalyst, the reaction solution can be cooled to crystallize the trichloropyridinol which is then isolated by filtration. If a soluble catalyst such as tetrabutylammonium chloride is used, the reaction solution can be cooled to crystallize the trichloropyridinol which is isolated by filtration. The filtrate containing the soluble catalyst can be recycled directly.
The present invention is illustrated by the following examples; however, these examples should not be construed as a limitation on the scope of the present claims. 6,327-F -12- -13- Example 1 Addition of Tr ichioroacetyl Chloride to Acrylonitrile TCAC VCN Freshly distilled tr ichioroacetyl chloride (TCAC), acrylonitrile (VCN) and anhydrous catalyst were heated under reflux in a nitrogen atmosphere. Percent conversion was determined by withdrawing, cooling, filtering and analyzing samples by gas chromatography (GC) or nuclear magnetic resonance (NMR) spectroscopy. Product was isolated by cooling the reaction mixture, evaporating the volatile starting materials and removing the catalyst by filtration. The results are summarized in Table I. 6,327-F -13- Table I PREPARATION OF 2 , 2 , 4-TRICHLORO-4-CYANOBUTANOYL CHLORID FROM TRICHLOROACETYL CHLORIDE (TCAC) AND ACRYLONITRILE ( TCAC contains an additional 15 WT% perohloroethylene recycle -15- Example 2 Cyclization of 2 , 2 , 4-Tr ichloro-4- -Cyanobutanoyl Chloride The cyclizations were carried out in a 600 milliliter (mL) Hastelloy C Bomb equipped with a magnetic drive. The 2 , 2 , 4-tr ichloro-4-cyanobutanoyl chloride was diluted with the desired solvent and the bomb pressurized with anhydrous HCl to the desired pressure. After stirring for the indicated time the bomb was vented and the contents transferred to a round bottom flask for evaporation on a rotary evaporator. The contents were slurried with hexane to facilitate isolation by filtration. The results are summarized in Table II. 6,327-F -15- - 1 6- TABLE II CYCLIZATION OF 2 , 2 , 4-TRICHLORO-4-CYANOBUTANOYL CHLORIDE TO 3 , 3 , 5 , 6-TETRACHLORO-3 , 4-DIHYDROPYRIDIN- -2-ONE a> ethylene dichloride Example 3 Aromatization of 3 , 3 » 5 , 6-Tetrachloro-3 , 4- -Dihydropyr idin-2-one : Two-Phase System H In a typical experiment 23 . 3 grams (g) ( 0 . 1 mol) of the dihydropyridone , 233 mL ethyl acetate, 233 mL water and 0 . 3 niol of base were stirred (magnetic stirrer) and refluxed for 2 hrs. After cooling, the reaction mixture was acidified with concentrated HC1 and the organic phase separated and dried over MgSOij. After filtration, the product was obtained by evaporation of the solvent from the filtrate. The results are summarized in Table III. 36 , 327-F - 16 - -17- TABLE III AROMATIZATION OF 3 , 3 , , 6-TETRACHLORO-3 , 4- -DIHYDROPYRIDIN-2-ONE TO 3 , , 6-TRICHLOROPYRIDIN-2-OL IN AN AQUEOUS TWO-PHASE SYSTEM ethylene dichloride ethyl acetate Example 4 Aromatization of 3 » 3 > 5 , 6-Tetrachloro-3 , 4- -Dihydropyridin-2-one : Nonaqueous To a 25 mL three neck round bottom flask was added 5 g of 3 » 3 * 5 , 6-tetrachloro-3 » 4-dihydropyridin-2- -one, 0.1 g of catalyst and 25 mL of solvent. The reaction mixture was heated to reflux and reaction progress was monitored by GC. Product was recovered by filtration. In each instance isolated yields were at least 90 percent. Table IV summarizes the catalysts and solvents employed. 36,327-F -17- -18- Table IV CATALYSTS AND SOLVENTS EMPLOYED IN NONAQUEOUS AROMATIZATION OF 3 , 3 , 5 , 6-TETRACHLORO-3 , 4- -DIHYDROPYRIDIN-2-ONE recycled 5 times recycled 10 times Example 5 Consecutive Cyclization-Aromatization The cyclizations were carried out in a 600 mL Hastelloy C bomb equipped with a magnetic drive. The 2,2, 4-trichloro- -cyanobutanoyl chloride (ADDUCT) was diluted with 150 mL of perchloroethylene and the bomb 6,327-F -18- -19- was pressurized to 150 psig (1,135 kPa) with anhydrous HC1. After stirring for 2 hrs at the indicated temperature, the bomb was vented and the contents transferred with the aid of an additional 100 mL of perchloroethylene to a round bottom flask containing MSA-1 Dow Ion Exchange Resin. The mixture was refluxed for 1.5 hrs and the solid catalyst was removed by filtration while hot. The filtrate was cooled to crystallize the 3 » 5 , 6-tr ichloro-pyridin-2-ol which was isolated by filtration and dried. The results are summarized in Table V.
TABLE V Cycl izat ion-Aromatizat ion 6,327-F - 1 9 -
Claims (6)
1. An improved process for the preparation of , 5 , 6-trichloropyridin-2-ol which comprises the following teps: (a) reacting trichloroacetyl chloride with acrylonitrile at a temperature from 50° to 140°C in the presence of a catalytic amount of copper or a cuprous salt to produce ■ 2 , 2 , 4-trichloro-4- cyanobutanoyl chloride while removing any HCl formed by operating' under reflux conditions; (b) reacting the 2 , 2 , 4-trichloro-4- cyanobutanoyl chloride in an inert organic solvent with anhydrous HCl at a pressure from 136 to 1.480 kPa and at a temperature from ambient to 100°C to cyclize the butanoyl chloride to 3 , 3 , 5 , 6-tetrachloro-3 , 4- dihydropyridin-2-one; and (c) reacting the 3 , 3 , 5 , 6-tetrachloro-3 , 4- dihydropyridin-2-one with chloride^and a phase transfer catalyst in an inert organic solvent to produce the 3 , 5 , 6-trichloro-2-pyridinol .
2. The process according to Claim 1 in step (a) which is performed from -'atmospheric pressure to a slight positive pressure of up to 136 kPa. 36, 327-F -20- -21-
3. The process according to Claim 1 in which the inert organic solvent in step (b) is an aromatic hydrocarbon, a halogenated hydrocarbon or a carboxylic acid ester.
4. The process according to Claim 1 in which the chloride ion in step (c) is generated in situ by elimination of HCl from the dihydropyridone . ±
5. The process according to Claim .-6* in which inert organic solvent is an aromatic hydrocarbon, a halogenated hydrocarbon or a carboxylic acid ester.
6. The process according to any one of Claims in which the reaction is conducted at a temperature from 40° to 120°C. 36, 327-F -21-
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/350,961 US4996323A (en) | 1989-05-12 | 1989-05-12 | Process for the preparation of 3,5,6-trichloropyridin-2-ol |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| IL94373A0 IL94373A0 (en) | 1991-03-10 |
| IL94373A true IL94373A (en) | 1994-06-24 |
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| Application Number | Title | Priority Date | Filing Date |
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| IL9437390A IL94373A (en) | 1989-05-12 | 1990-05-13 | Process for the preparation of 3,5,6-trichloropyridin-2-ol |
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| Country | Link |
|---|---|
| US (1) | US4996323A (en) |
| EP (1) | EP0397281B1 (en) |
| JP (1) | JP2829342B2 (en) |
| KR (1) | KR0153446B1 (en) |
| CN (1) | CN1027259C (en) |
| AT (1) | ATE144979T1 (en) |
| AU (1) | AU620245B2 (en) |
| BR (1) | BR9001798A (en) |
| CA (1) | CA2016620C (en) |
| DE (1) | DE69029052T2 (en) |
| DK (1) | DK0397281T3 (en) |
| ES (1) | ES2095854T3 (en) |
| FI (1) | FI97132C (en) |
| HU (2) | HU205078B (en) |
| IL (1) | IL94373A (en) |
| MX (1) | MX166335B (en) |
| NZ (1) | NZ233615A (en) |
| RU (1) | RU1839671C (en) |
| UA (1) | UA19168A1 (en) |
Families Citing this family (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IL86341A (en) * | 1988-05-11 | 1992-02-16 | Pamol Ltd | Preparation of polychloropyridine derivatives and intermediates therefor |
| US5254712A (en) * | 1990-01-06 | 1993-10-19 | Stamicarbon B.V. | Process for the preparation of 5-oxohexane nitriles and the compound 2,4-dimethyl-5-oxohexane nitrile |
| NL9000034A (en) * | 1990-01-06 | 1991-08-01 | Stamicarbon | PROCESS FOR THE PREPARATION OF 5-OXOHEXANE NITRILLES AND THE SUBSTANCE 2,4-DIMETHYL-5-OXOHEXANE NITRILLES. |
| US5618942A (en) * | 1993-09-03 | 1997-04-08 | Luxembourg Industries (Pamol) Ltd. | Production of 2,3,5,6-tetrachloropyridine |
| US5688953A (en) * | 1996-07-31 | 1997-11-18 | Dowelanco | Process for the preparation of 3,3,5-trichloroglutarimide |
| CN102351785B (en) * | 2011-08-11 | 2013-05-01 | 江苏九九久科技股份有限公司 | Method for preparing 3, 5, 6-trichloropyridin-2-ol sodium |
| CN103086961A (en) * | 2011-10-27 | 2013-05-08 | 山西三维丰海化工有限公司 | Method for producing pyridone from chloroacetic acid waste liquid |
| CN103086960A (en) * | 2011-10-27 | 2013-05-08 | 山西康得利精细化工有限公司 | Novel process for producing chlopyrifos from pyridone by using aqueous phase method |
| CN103086959A (en) * | 2011-10-27 | 2013-05-08 | 山西三维丰海化工有限公司 | Novel process for producing 3,5,6-sodium trichloropyrindinol |
| CN103193705A (en) * | 2013-03-22 | 2013-07-10 | 浙江工业大学 | Synthesis method of 2-chloronicotinic acid and derivative thereof |
| CN103274996B (en) * | 2013-05-02 | 2015-08-19 | 江苏九九久科技股份有限公司 | The one kettle way of improvement prepares the method for 3,5,6-trichloropyridine-2-sodium alkoxide |
| CN103819397B (en) * | 2014-03-14 | 2015-12-30 | 杨雪飞 | A kind of efficient catalytic synthetic method of heterocyclic alcohol |
| CN104876858A (en) * | 2015-05-13 | 2015-09-02 | 安徽国星生物化学有限公司 | One-pot method for synthesizing sodium 3,5,6-trichloropyridin-2-olate |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3007931A (en) * | 1959-03-09 | 1961-11-07 | Phillips Petroleum Co | Production of unsaturated heterocyclic nitrogen bases |
| US4245098A (en) * | 1978-12-05 | 1981-01-13 | Ciba-Geigy Corporation | Process for producing 2,3,5-trichloropyridine, 2,4,4-trichloro-4-formyl-butyronitrile as a novel compound and a process for producing it |
| DE3070085D1 (en) * | 1979-11-30 | 1985-03-14 | Ciba Geigy Ag | Process for the preparation of 2,3,5,6-tetrachloropyridine and 3,5,6-trichloropyridin-2-ol |
| US4469896A (en) * | 1981-08-17 | 1984-09-04 | Ciba-Geigy Corporation | Process for the production of chloropyridines substituted by methyl, trichloromethyl or trifluoromethyl groups |
| US4435573A (en) * | 1982-10-25 | 1984-03-06 | The Dow Chemical Company | Process for the preparation of substituted pyridines |
| US4468354A (en) * | 1983-02-15 | 1984-08-28 | The Dow Chemical Company | Continuous process for preparing 5-oxo-2,4-dichloro-4-substituted pentanenitriles |
| US4465186A (en) * | 1983-07-14 | 1984-08-14 | Meyers Jonathan H | Holder for clips |
| AR243869A1 (en) * | 1987-06-05 | 1993-09-30 | Quimica Estrella Aca Sa | A procedure for synthesising 2-hydroxy-3,5,6-trichloropyridine. |
| JPS63313771A (en) * | 1987-06-15 | 1988-12-21 | Nippon Kayaku Co Ltd | Production of 3,5,6-trichloro-2-pyridinol |
| IL86341A (en) * | 1988-05-11 | 1992-02-16 | Pamol Ltd | Preparation of polychloropyridine derivatives and intermediates therefor |
-
1989
- 1989-05-12 US US07/350,961 patent/US4996323A/en not_active Expired - Lifetime
-
1990
- 1990-04-11 BR BR909001798A patent/BR9001798A/en not_active IP Right Cessation
- 1990-05-09 NZ NZ233615A patent/NZ233615A/en unknown
- 1990-05-11 AT AT90201193T patent/ATE144979T1/en not_active IP Right Cessation
- 1990-05-11 KR KR1019900006675A patent/KR0153446B1/en not_active IP Right Cessation
- 1990-05-11 HU HU903008A patent/HU205078B/en not_active IP Right Cessation
- 1990-05-11 RU SU904743820A patent/RU1839671C/en active
- 1990-05-11 CA CA002016620A patent/CA2016620C/en not_active Expired - Fee Related
- 1990-05-11 HU HU913709A patent/HU913709D0/en unknown
- 1990-05-11 FI FI902363A patent/FI97132C/en not_active IP Right Cessation
- 1990-05-11 JP JP2122854A patent/JP2829342B2/en not_active Expired - Lifetime
- 1990-05-11 DK DK90201193.1T patent/DK0397281T3/en active
- 1990-05-11 AU AU54945/90A patent/AU620245B2/en not_active Expired
- 1990-05-11 EP EP90201193A patent/EP0397281B1/en not_active Expired - Lifetime
- 1990-05-11 UA UA4743820A patent/UA19168A1/en unknown
- 1990-05-11 CN CN90102727A patent/CN1027259C/en not_active Expired - Lifetime
- 1990-05-11 ES ES90201193T patent/ES2095854T3/en not_active Expired - Lifetime
- 1990-05-11 MX MX020686A patent/MX166335B/en unknown
- 1990-05-11 DE DE69029052T patent/DE69029052T2/en not_active Expired - Fee Related
- 1990-05-13 IL IL9437390A patent/IL94373A/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| CN1047281A (en) | 1990-11-28 |
| FI97132C (en) | 1996-10-25 |
| HU205078B (en) | 1992-03-30 |
| AU5494590A (en) | 1990-11-15 |
| KR0153446B1 (en) | 1998-11-16 |
| US4996323A (en) | 1991-02-26 |
| NZ233615A (en) | 1992-06-25 |
| HU913709D0 (en) | 1992-02-28 |
| ATE144979T1 (en) | 1996-11-15 |
| UA19168A1 (en) | 1997-12-25 |
| AU620245B2 (en) | 1992-02-13 |
| DE69029052D1 (en) | 1996-12-12 |
| CA2016620A1 (en) | 1990-11-12 |
| JPH035458A (en) | 1991-01-11 |
| HU903008D0 (en) | 1990-09-28 |
| DE69029052T2 (en) | 1997-03-06 |
| CN1027259C (en) | 1995-01-04 |
| FI97132B (en) | 1996-07-15 |
| DK0397281T3 (en) | 1997-04-14 |
| RU1839671C (en) | 1993-12-30 |
| KR900018028A (en) | 1990-12-20 |
| FI902363A0 (en) | 1990-05-11 |
| IL94373A0 (en) | 1991-03-10 |
| EP0397281B1 (en) | 1996-11-06 |
| BR9001798A (en) | 1991-06-11 |
| MX166335B (en) | 1992-12-29 |
| ES2095854T3 (en) | 1997-03-01 |
| CA2016620C (en) | 2001-05-08 |
| EP0397281A3 (en) | 1991-10-02 |
| JP2829342B2 (en) | 1998-11-25 |
| HUT54984A (en) | 1991-04-29 |
| EP0397281A2 (en) | 1990-11-14 |
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